Electrical plug support bracket

ABSTRACT

A substantially rigid plastic plug support bracket is provided for supporting an electrical plug which is detachably mounted in a receptacle therefor on a vehicular body such as the wall of a trailer of a tractor-trailer vehicle. The plastic plug support bracket includes a base portion and a plug supporting portion pivotally connected thereto. The base portion includes a substantially V-shaped base plate which is secured through holes therein to a receptacle for the electrical plug. The base portion further includes, at the bottom of the plate, a pair of spaced parallel pivot brackets which extend from and are perpendicular to one face of the base plate. The plug supporting portion includes an elongated arm and a substantially semi-circular band connected, at the mid-point of its periphery, integrally to one end of said arm with the interior of the band facing away from the arm. The interior of the band is shaped to conform to an axially extending portion of the lower semi-circular half of the electrical plug which is substantially circular in cross-section. The other end of the arm is pivotally connected to and between the pivot brackets. The other end of the arm is substantially rectangular in cross-section and includes a face on each side thereof which frictionally abuts a face of a respective one of said pair of pivot brackets to frictionally hold the plug supporting portion against free pivotal movement relative to the base portion. The base portion also includes a spacer member, adjacent the bottom of the base plate, which extends from the other face of the base plate. The spacer member fills a portion of the space between the plug support bracket and the panel of the vehicle when the plug support bracket is connected to the receptacle to thereby provide additional support for the plug support bracket.

United States Patent [191 Burkle [4 1 Oct. 28, 1975 ELECTRICAL PLUG SUPPORT BRACKET [75] Inventor: Robert Burkle, New Haven, Conn.

[73] Assignee: Autac Incorporated, New Haven,

Conn.

[22] Filed: Jan. 16, 1975 [21] Appl. No.: 541,399

[52] US. Cl. 280/422; 339/10; 339/75 P [51] Int. Cl. H01R 13/44 [58] Field of Search 280/422, 421; 339/103 R,

339/103 M, 75 P, 10, 43, 44 R, 44 M Primary ExaminerLeo Friaglia Attorney, Agent, or Firm-Clelle W. Upchurch [5 7] ABSTRACT A substantially rigid plastic plug support bracket is provided for supporting an electrical plug which is detachably mounted in a receptacle therefor on a vehicular body such as the wall of a trailer of a tractortrailer vehicle. The plastic plug support bracket includes a base portion and a plug supporting portion pivotally connected thereto. The base portion includes a substantially V-shaped base plate which is secured through holes therein to a receptacle for the electrical plug. The base portion further includes, at the bottom of the plate, a pair of spaced parallel pivot brackets which extend from and are perpendicular to one face of the base plate. The plug supporting portion includes an elongated arm and a substantially semi-circular band connected, at the mid-point of its periphery, integrally to one end of said arm with the interior of the band facing away from the arm. The interior of the band is shaped to conform to an axially extending portion of the lower semi-circular half of the electrical plug which is substantially circular in cross-section. The other end of the arm is pivotally connected to and between the pivot brackets. The other end of the arm is substantially rectangular in cross-section and includes a face on each side thereof which frictionally abuts a face of a respective one of said pair of pivot brackets to frictionally hold the plug supporting portion against free pivotal movement relative to the base portion. The base portion also includes a spacer member, adjacent the bottom of the base plate, which extends from the other face of the base plate. The spacer member fills a portion of the space between the plug support bracket and the panel of the vehicle when the plug support bracket is connected to the receptacle to thereby provide additional support for the plug support bracket.

8 Claims, 5 Drawing Figures Sheet 1 of 2 US. Patent 0a. 28, 1975 U.S. Patent Oct. 28, 1975 Sheet 2 of2 3,915,476

FIG. 4

HIIIIIIIHHIII A FIG; 3

ELECTRICAL PLUG SUPPORT BRACKET BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a plastic plug support bracket which supports an electrical, plug which is detachably mounted in a receptacle therefor on a panel of a vehicular body, such as the forwardmost panel of a trailer of a tractor-trailer type vehicle.

2. Description of the Prior Art The electrical system of the trailer of a tractor-trailer vehicle is detachably connected to that of the tractor by means of one or more plug and electrical receptacle assemblies. The receptacle member of the assembly is usually mounted on the front panel of the trailer and/or the rear panel of the tractor and the plug member is fastened to the ends of a cable which leads from the tractor to lights and the like on the trailer. The receptacle member has a cylindrical body enclosing a plurality of prongs which are inserted in corresponding electrically conductive bores in the plug each secured to a wire of the cable. A flange is provided about the cylindrical body for fastening the receptacle to the trailer. Since the plug is a relatively large and heavy metallic or molded cylindrical member, it must be supported externally of the receptacle to prevent it from being shaken loose from the receptacle while the vehicle is being operated.

Metal plug support brackets for supporting the electrical plug detachably mounted in the receptacle are known in the prior art. However, these metal plug support brackets have proven to be disadvantageous for several reasons. First, the metal brackets are extremely brittle and are easily broken when subjected to the vibration transmitted to them from the operation of the vehicle on which they are mounted. This breaking is even more pronounced when the bracket is used in a low temperature environment of for example, 32F or lower. As the vehicles on which these brackets are mounted sometimes travel in low temperature regions, they are often subjected to these low temperatures and therefore frequently break and cause down-time for the vehicle for repairs. Secondly, in the prior art metal plug support brackets, the plug supporting portion is freely pivotally connected to the base portion so that when the plug is disconnected from the receptacle, the plug supporting portion is continually, again by reason of the vibration to which it is subjected by the vehicle in operation, pivoting freely from the base portion and slapping or knocking against the panel of the vehicle which of course is a nuisance to the vehicle driver. Furthermore, this continual slapping or knocking is a further cause of the above-noted breaking problem of the prior art metal bracket. Thirdly, because the prior art plug support bracket is made of metal, the interior of the semi-circular band of the plug supporting portion must be machined after it is made so that its shape will conform to the axial extending portion of the lower semi-circular half of the electrical plug which it was made to support. This cumbersome machining increases the cost of such brackets.

SUMMARY OF THE INVENTION In accordance with this invention, a substantially rigid plastic plug support bracket which is resistant to damage by impact, impervious to gas, oil, grease, ultra violet rays and ozone. and will remain stable at temperatures of from 75F to +400F is provided. By providing a substantially plastic plug support bracket as in the invention, the bracket is not easily broken and is in fact substantially impact-proof even at low temperatures down to 75F or lower.

Also, by providing a substantially rigid plastic plug support bracket as in the invention, if the plug is made by injection molding or other known processes, the interior of the semi-circular band of the plug supporting portion is shaped to conform. to the axially extending portion of the semi-circular lower half of an electrical plug which is circular in crosssection and does not have to be subsequently machined to obtain the desired shape. Therefore, with the invention this otherwise cumbersome machining is not needed and should therefore reduce the unit production cost of the plug support bracket.

Also, in the invention, the transverse dimension of one end of the arm is substantially equal to the space between the pivot brackets so that the plug supporting portion of the bracket is frictionally held against free pivotal movement relative to the base portion by the frictional interface between the end of the arm and the pivot brackets. ln the advantageous embodiment to be described, the end of the arm is substantially rectangular in cross-section to provide a face on each side of it which frictionally abuts a face ofa respective one of the pair of pivot brackets to frictionally hold the plug supporting bracket against free pivotal movement relative to the base portion. As a result of this aspect of the invention, the plug supporting portion is not freely pivotable relative to the base portion and therefore does not slap or knock against the panel of the vehicular body to which it is attached so that the nuisance caused to the operator of the vehicle by such slapping or knocking as well as thebreakage of the bracket which may be caused by it is eliminated.

[t is an ojbect of this invention to provide a plastic plug support bracket which is substantially impactproof and cannot be broken or rendered in any way inoperative when mounted on a vehicle when the vehicle is in normal operation.

It is a further object of this invention to provide a plastic plug support bracket which is impervious to gas, oil, and grease.

It is a further object of this invention to provide a plastic plug support bracket which is impervious to ultraviolet rays and ozone.

It is a further object of this invention to provide a plastic plug support bracket which will remain stable at temperatures from -F to +400F.

It is a further object of this invention to provide a plastic plug support bracket which is not easily broken during normal operation of the vehicle on which it is mounted. 1

It is a further object of this invention to provide a plastic plug support bracket which is not easily broken during normal operation of the vehicle on which it is mounted, particularly one which is not easily broken at temperatures down to 75F.

It is a still further object of this invention to provide a plastic plug support bracket which does not require any subsequent combersome machining of any portion thereof after the bracket is completed.

It is a still further object of this invention to provide a plastic plug support bracket in which the plug supporting portion is not freely pivotable relative to the base portion thereof so that the plug supporting portion is thereby prevented from slapping or knocking against the panel ofa vehicle on which the bracket is mounted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing the forward panel of the trailer of a tractor-trailer type vehicle.

FIG. 2 is a perspective view showing the panel of the vehicle with the receptacle mounted thereon and the substantially rigid plastic plug support bracket connected to the receptacle with the electrical plug mounted in the receptacle and the plug supporting portion of the bracket supporting the plug.

FIG. 3 is a view similar to FIG. 2 but showing the plug disconnected from the receptacle and the plug supporting portion of the substantially rigid plastic plug support bracket 'out of its supporting position.

FIG. 4 is a side view, looking in the direction in which the plug is inserted, of the substantially rigid plastic plug support bracket mounted on a panel with the plug supporting portion of the bracket in its supporting position.

FIG. 5 is a view taken along line 5-5 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, is shown a tractor-trailer T. On the forwardmost p'anel P of the trailer of the vehicle are positioned a plurality of electrical receptacles which receive a respective one of a corresponding number of electrical plugs 11. The receptacles l0 and electrical plugs 11 received therein are well-known in the prior art. The purpose of the connection ofthe plug 11 into the receptacle 10 is to provide power to the trailer from the tractor for the lights or other power equipment, such as a refrigeration unit, in the trailer.

As shown in FIG. 3, each receptacle 10 includes a plurality of male prongs 12. Each prong 12 is received in a' respective one of a plurality of openings 13 in the plug 11 when the plug is connected into the receptacle. To further lock the plug in the receptacle, the receptacle has a longitudinal notch 14 cut into the upper portion of the interior surface thereof. A key 15 is provided on the exterior surface of the plug 11. The key 15 is shaped complementary to the notch 14 so as to further assist in locking and prevent rotation of the plug 11 in the receptacle 10. However, as is known in the prior art, by reason of the vibration to which the plug 11 and receptacle 10 are subjected by the operation of the vehicle on which they are mountedythe plug 11 tends to move or walk out of the receptacle 10 which of course results in a disconnection of the power from the tractor to the trailer of the tractor-trailer T. This cutoff of power to the trailer of course results in unnecessary and sometimes expensive down-time of any equipment, such as refrigeration units, in the trailer.

To prevent this unnecessary disconnection of the plug 11 from the receptacle 10, the invention provides a substantially rigid plastic plug support bracket 20. The plug support bracket comprises a base portion and a plug supporting portion 40 which is pivotally connected to the base portion 30.

The base portion 30 comprises a substantially V- shaped base plate 31 with legs 34, and a substantially semi-circular upper edge 32 therebetween (FIG. 4). The edge 32 is shaped so that it may be positioned around the lower half of the substantially circular plug receiving portion of the receptacle 10. Each of the legs 34, 35 of the V-shaped base plate 31 has an aperture 33 therein. A bolt or screw 50. is inserted through each aperture 33 to secure it to the receptacle 10. As the receptacles of the prior art are provided with holes to secure them to the panel of the vehicle, it is desirable that the aperture 33 in each leg 34, 35 be spaced identical to the holes in the prior art receptacle so that the bolts or screws 50 can then be used to mount both the receptacle 10 and plug support bracket to the panel P of the vehicle as shown in FIG. 5.

The base portion 30 further includes, at the bottom of the base plate 31, a pair of spaced parallel pivot brackets 36. Each pivot bracket 36 extends from and is substantially perpendicular to the face 31a of base plate 31.

The plug supporting portion 40 of the substantially rigid plastic plug support bracket 20 includes an elongated arm 41 and a substantially semi-circular band 46. The band 46 is integrally connected, at the mid-point of its periphery, to one end v42 of the arm 41. The interior surface 46a of the band 46 is shaped to conform to the lower semi-circular half of the electrical plug 11. The length of arm 41 is such that when member 40 is in its supporting position shown in FIGS. 4 and 5, the upper surface of plug 11 is pressed against the inner surface of receptacle 10. In other words, the length of arm 41 from the pivot point to the inner surface of member 46 along the longitudinal axis of arm 41 is slightly larger than the distance between the pivot point and the bottom of the plug in its normal inserted position where its axis coincides with that of receptacle 10 so that the plug is pushed upwardly so its axis is no longer parallel to the axis of the receptacle. The other end 43 of the arm 41 is substantially rectangular in cross-section, as shown in FIGS. 2 through 4, to provide a pair of faces 43a, 43b which frictionally abut the faces 36', 36" of the pair of pivot brackets 36 (FIG. 4). The end 43 has a transverse dimension which is substantially equal to the space d between the pair of pivot brackets 36. By reason of the structural conformation of the end 43 of the arm 41 relative to that of the pair of pivot brackets 36, the plug supporting portion 40 of the plug support bracket 20 is held against free pivotal movement relative to the base portion 30 by the frictional interface formed between the faces 43a, 43b of the end 43 of the arm 41 and the faces 36, 36" of the pivot brackets 36. As the plug supporting portion 40 of the plug support bracket 20 is not freely pivotable relative to the base portin 30, it will not slap or knock against the panel P when the plug supporting portion is not in use in supporting the plug 11. A strengthing rib 44 extends from the base member 43 along each side of arm 41 and semi-circular member 42.

The base portion 30 of the plug support bracket 20 also includes a spacer member 37 which extends from the other face 31b of the base plate 31. The spacer member 37 may be substantially circular in crosssection and is provided to take up the space between the lower portion of the base plate 31 and the panel P in the region below the receptacle 10. As the spacer member 37 is in abutment with the portion of the panel P, it provides additional support for the plug support bracket 20.

To provide the pivotal connection between the base portion 30 and the plug supporting portion 40, an aperture 36a is provided in each of the pivot brackets 36 and an aperture 43' is formed in the end 43 of the arm 41. A pin 38 extends through these apertures so that' the arm 41 may pivot about the axis of the pin relative to the base portion 30.

The operation of the invention will now be described. When the operator of a vehicle-desires to provide an electrical connection from the tractor portion of the tractor-trailer T to the trailer, he merely lifts up the cap a closing the opening of the receptacle, and, by rea' son of the alignment made by the key on the plug 11 with the notch 14 in the receptacle 10, forceably inserts the plug 11 into the receptacle 10. To prevent the plug 10 from slipping or walking out of the receptacle 10, the-operator then moves the plug supporting portion of the plug support bracket from a lower position as in FIG. 3, up into its position beneath the plug 11 into the plug supporting position shown in FIGS. 2, 4 and 5. In this position the plug support bracket, with the interior surface 46a of the semi-circular band 46 supportingly abutting an axial portion of the lower half of the semi-circular surface of the plug 11, provides additional support for the plug 11 in the receptacle l0 and prevents the plug from moving orwalking out of the receptacle. Also as noted above, additional support is also provided by the abutment of the spacer member 37 with the portion of the panel P below the receptacle 10 as shown in FIG. 5.

When the operator desires to disconnect the plug 11 from the receptacle 10, he merely pulls the plug supporting portion 40 of the plug support bracket 20 outwardly and downwardly to pivot it about the axis of the pin 38 back to a lower position such as the one shown in FIG. 3. The operator then merely withdraws the plug 1 1 from the receptacle 10 at which time the closure cap 10a of the receptacle 10, by reason of its being spring biased to a closed position, covers the receptacle 10 to prevent dirt or other foreign matter from entering therein.

The plug support bracket 20 of this invention may be made by any plastic or thermo-plastic which is substantially impact-proof, impervious to gas, oil, grease, ultraviolet rays and ozone and will remain stable at temperatures from -75F to +400F. One example of such a plastic is Valox, a moldable (polyethylene terephthalate) polyester which is commercially available from the General Electric Company. It will of course occur to persons skilled in the art that many other plastics or thermo-plastics having the above characteristics are suitable for this invention.

The plug support bracket 20 of this invention is therefore virtually unbreakable at all normal operating temperatures to which the vehicle on which it is mounted would normally be subjected. Furthermore, by reason of the frictional interface in the pivotal connection between the plug supporting portion and the base portion of the plug support bracket 20, the plug supporting portion does not slap or knock against the panel and therefore is not a nuisance to the operator of the vehicle and will not cause breakage of the bracket. Furthermore, when this bracket is made, the interior face 46a of the band 46 requires no further machining in order to have it conform as closely as possible to the lower periphery of the plug 11.

While the plug support bracket of this invention has been described above in connection with the tractortrailer type vehicle, it will occur to persons skilled in the art that the plug support bracket is useable in any environment where the priorart plugs and receptacles have been used and is particularly useful in environments where the prior art plugs and receptacles are subjected for any reason to substantial vibration. For example, these receptacles'hav'e been mounted on the rear panel of thhe tractor of the tractor-trailer vehicle and on other types of vehicles such as refrigeration trucks, milk trucks, to provide an electrical connection to them from a main power source apart from the vehicle when the vehicle is otherwise inoperative.

It is evident from the above description that, by means of this invention, the deficiencies of the prior art metal plug support bracket are: overcome.

What is claimed is:

l. A substantially rigid plastic plug support bracket adapted to support an electrical plug detachably mounted in a receptacle therefor on a vehicular body, said bracket comprising:

a base portion, said base portion comprising a base plate, adapted to lie in a vertical plane when secured to a receptacle and, at the bottom of said plate, a pair of spaced parallel pivot brackets ex tending from and substantially perpendicularto one face of said base plate, and l a plug supporting portion comprising an elongated arm and a substantially semi-circular band connected, at the mid-point of its periphery, integrally to one end of said arm with the interior of s'aid band facing away from said arm, the substantially semicircular interior surface of said band being shaped to conform to an axially extending portion of the lower semi-circular half of an electrical plug, substantially circular in cross-section, which the plug supporting portion is adapted to support, the other end of said arm being pivotally connected to and between said pivot brackets, said end of said arm having a transverse dimension substantially equal to the space between said pivot brackets so that said plug supporting portion is frictionally held against free pivotal movement relative to the base portion by the frictional interface between the one end of said arm and said pivot brackets.

2. A substantially rigid plastic plug support bracket as claimed in claim 1, wherein;

the one end of said arm is substantially rectangular in cross-section to provide a face on each side thereof which frictionally abuts a face of a respective one of said pair of pivot brackets to frictionally hold said plug supporting portion against free pivotal movement relative to the base portion.

3. A substantially rigid plastic plug support bracket as claimed in claim 2, further comprising:

means defining an aperture in each of said pivot brackets,

means defining an aperture in said one end of said arm,

said pivot bracket apertures and said arm aperture being aligned, and

a pin force fitted in and extending through the aperture in said arm and into the aperture in each of said pivot brackets whereby said arm is pivotable about the axis of said pin.

4. A substantially rigid plastic plug support bracket as claimed in claim 3, wherein said base plate is substantially Vshaped in cross-section with the upper edge thereof being substantially semi-circular so as to be positioned around the lower half of a substantially circular plug receiving portion of a receptacle to which i the base portion is adapted to be secured, and

means defining an aperture in the upper end portion of each leg of the V-shaped base plate through which a securing means may be inserted to secure the base portion to a receptacle.

5. A substantially rigid plastic plug support bracket as claimed in claim 4, wherein:

said base portion further comprises, adjacent the bottom of said base plate, a spacer member which extends from the other face of said base plate, said spacer member being adapted to abut a vehicular body and thereby provide additional support for the plug support bracket when secured to a receptacle therefor on a vehicular body.

6. A substantially rigid plastic plug support bracket as claimed in claim 5, wherein:

the plug support bracket is substantially impactproof, impervious to gas, oil, grease, ultraviolet rays and ozone and remains stable at temperatures from 75F to +400F.

7. An electrical plug and receptacle assembly comprising a receptacle having a cylindrical plug receiving means and a flange adapted to be fastened to a wall of a tractor or trailer of a tractor-trailer vehicle and a cylindrical plug insertable in said receptacle to connect electrically a power source on the tractor with an electrical circuit of a trailer, and means for supporting the plug in the receptacle comprising a molded rigid plastic bracket having a generally V-shaped plate member de- :tachably secured to the saidflange on the receptacle with its legs straddling the plug receiving means and its base disposed below the plug receiving means, a pair of laterally spaced plate members integral with the base of said plate member and projecting outwardly therefrom below said plug receiving means, a plug support member having a base portion pivotally secured between said laterally spaced plate members and frictionally engaging them to retard pivoting movement of the plug support member therebetween, said plug support member having a semi-circular member disposed about said cylindrical plug and pressing the plug upwardly against the inner wall of the receptacle andan elongated arm portion integral at one end to said base portion and at the other end to said semi-circular member, the length of said plug support member between its pivot point and its supporting semi-circular surface being greater than the distance between the pivot point and the underside of the cylindrical plug when the said cylindrical plug and receptacle are coaxial whereby said plug support member exerts a pressure against the said plug and causes it to become bound in the receptacle.

8. The assembly of claim 7 wherein the said plug support member has a strengthening ribv extending along each side of the arm portion and said semi-circular member, the width of the ribs plus the width of the arm being substantially equal to the width of the base portion. i 

1. A substantially rigid plastic plug support bracket adapted to support an electrical plug detachably mounted in a receptacle therefor on a vehicular body, said bracket comprising: a base portion, said base portion comprising a base plate, adapted to lie in a vertical plane when secured to a receptacle and, at the bottom of said plate, a pair of spaced parallel pivot brackets extending from and substantially perpendicular to one face of said base plate, and a plug supporting portion comprising an elongated arm and a substantially semi-circular band connected, at the mid-point of its periphery, integrally to one end of said arm with the interior of said band facing away from said arm, the substantially semi-circular interior surface of said band being shaped to conform to an axially extending portion of the lower semi-circular half of an electrical plug, substantially circular in cross-section, which the plug supporting portion is adapted to support, the other end of said arm being pivotally connected to and between said pivot brackets, said end of said arm having a transverse dimension substantially equal to the space between said pivot brackets so that said plug supporting portion is frictionally held against free pivotal movement relative to the base portion by the frictional interface between the one end of said arm and said pivot brackets.
 2. A substantially rigid plastic plug support bracket as claimed in claim 1, wherein: the one end of said arm is substantially rectangular in cross-section to provide a face on each side thereof which frictionally abuts a face of a respective one of said pair of pivot brackets to frictionally hold said plug supporting portion against free pivotal movement relative to the base portion.
 3. A substantially rigid plastic plug support bracket as claimed in claim 2, further comprising: means defining an aperture in each of said pivot brackets, means defining an aperture in said one end of said arm, said pivot bracket apertures and said arm aperture being aligned, and a pin force fitted in and extending through the aperture in said arm and into the aperture in each of said pivot brackets whereby said arm is pivotable about the axis of said pin.
 4. A substantially rigid plastic plug support bracket as claimed in claim 3, wherein said base plate is substantially V-shaped in cross-section with the upper edge thereof being substantially semi-circular so as to be positioned around the lower half of a substantially circular plug receiving portion of a receptacle to which the base portion is adapted to be secured, and means defining an aperture in the upper end portion of each leg of the V-shaped base plate through which a securing means may be inserted to secure the base portion to a receptacle.
 5. A substantially rigid plastic plug support bracket as claimed in claim 4, wherein: said base portion further comprises, adjacent the bottom of said base plate, a spacer member which extends from the other face of said base plate, said spacer member being adapted to abut a vehicular body and thereby provide additional support for the plug support bracket when secured to a receptacle therefor on a vehicular body.
 6. A substantially rigid plastic plug support bracket as claimed in claim 5, wherein: the plug support bracket is substantially impact-proof, impervious to gas, oil, grease, ultraviolet rays and ozone and remains stable at temperatures from -75*F to +400*F.
 7. An elEctrical plug and receptacle assembly comprising a receptacle having a cylindrical plug receiving means and a flange adapted to be fastened to a wall of a tractor or trailer of a tractor-trailer vehicle and a cylindrical plug insertable in said receptacle to connect electrically a power source on the tractor with an electrical circuit of a trailer, and means for supporting the plug in the receptacle comprising a molded rigid plastic bracket having a generally V-shaped plate member detachably secured to the said flange on the receptacle with its legs straddling the plug receiving means and its base disposed below the plug receiving means, a pair of laterally spaced plate members integral with the base of said plate member and projecting outwardly therefrom below said plug receiving means, a plug support member having a base portion pivotally secured between said laterally spaced plate members and frictionally engaging them to retard pivoting movement of the plug support member therebetween, said plug support member having a semi-circular member disposed about said cylindrical plug and pressing the plug upwardly against the inner wall of the receptacle and an elongated arm portion integral at one end to said base portion and at the other end to said semi-circular member, the length of said plug support member between its pivot point and its supporting semi-circular surface being greater than the distance between the pivot point and the underside of the cylindrical plug when the said cylindrical plug and receptacle are coaxial whereby said plug support member exerts a pressure against the said plug and causes it to become bound in the receptacle.
 8. The assembly of claim 7 wherein the said plug support member has a strengthening rib extending along each side of the arm portion and said semi-circular member, the width of the ribs plus the width of the arm being substantially equal to the width of the base portion. 